Yamaha F20BMHS v3 Owner's Manual
![Yamaha F20BMHS manual cover](/images/5194961792713f88c27473c2/thumbs/thumb175x175.webp)
The Yamaha F20BMHS should undergo routine maintenance every 100 hours of operation or annually, whichever comes first. This includes checking and replacing the engine oil, inspecting the fuel system, cleaning the spark plugs, and examining the propeller for damage.
If the Yamaha F20BMHS is having starting issues, check the fuel supply, ensure that the fuel tank is full, and that the fuel lines are not blocked. Also, inspect the spark plugs for fouling and verify that the battery is fully charged if using an electric start.
Yamaha recommends using Yamalube 4M FC-W 10W-30 oil for optimal performance of the F20BMHS. Make sure to use oil that meets the NMMA FC-W certification.
To prevent corrosion, rinse the outboard motor with fresh water after each use, especially after saltwater exposure. Apply a protective anti-corrosion spray to metal parts and store the motor in a dry place when not in use.
If overheating occurs, check the water intake for blockages and ensure the water pump impeller is functioning properly. Also, verify the coolant passages are clear and not obstructed by debris or salt deposits.
To winterize the F20BMHS, drain the fuel system, stabilize the remaining fuel, change the engine oil, and apply fogging oil to the cylinders. Remove the battery and store it in a cool, dry place.
To change the propeller, remove the cotter pin and propeller nut, slide off the old propeller, and inspect the shaft for damage. Apply marine grease to the shaft, install the new propeller, secure it with the nut, and replace the cotter pin.
To improve fuel efficiency, ensure the outboard is properly trimmed, maintain a steady cruising speed, and avoid carrying unnecessary weight on the boat. Regular maintenance, like keeping the propeller clean, also helps.
Signs that the water pump impeller needs replacement include reduced water flow from the tell-tale, engine overheating, or unusual noises from the lower unit.
To adjust the idle speed, locate the idle adjustment screw on the carburetor. Turn the screw clockwise to increase idle speed or counterclockwise to decrease it. Refer to the manual for the correct RPM settings.